| 131. |
- Sayin, Sama I., et al.
(författare)
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Gut microbiota regulates bile acid metabolism by reducing the levels of tauro-beta-muricholic acid, a naturally occurring FXR antagonist.
- 2013
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Ingår i: Cell metabolism. - : Elsevier BV. - 1932-7420 .- 1550-4131. ; 17:2, s. 225-35
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Tidskriftsartikel (refereegranskat)abstract
- Bile acids are synthesized from cholesterol in the liver and further metabolized by the gut microbiota into secondary bile acids. Bile acid synthesis is under negative feedback control through activation of the nuclear receptor farnesoid X receptor (FXR) in the ileum and liver. Here we profiled the bile acid composition throughout the enterohepatic system in germ-free (GF) and conventionally raised (CONV-R) mice. We confirmed a dramatic reduction in muricholic acid, but not cholic acid, levels in CONV-R mice. Rederivation of Fxr-deficient mice as GF demonstrated that the gut microbiota regulated expression of fibroblast growth factor 15 in the ileum and cholesterol 7α-hydroxylase (CYP7A1) in the liver by FXR-dependent mechanisms. Importantly, we identified tauro-conjugated beta- and alpha-muricholic acids as FXR antagonists. These studies suggest that the gut microbiota not only regulates secondary bile acid metabolism but also inhibits bile acid synthesis in the liver by alleviating FXR inhibition in the ileum.
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| 132. |
- Schneider, K. M., et al.
(författare)
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Gut microbiota depletion exacerbates cholestatic liver injury via loss of FXR signalling
- 2021
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Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 3:9, s. 1228-1241
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Tidskriftsartikel (refereegranskat)abstract
- Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology for which there are no approved therapeutic options. Patients with PSC display changes in gut microbiota and in bile acid (BA) composition; however, the contribution of these alterations to disease pathogenesis remains controversial. Here we identify a role for microbiota-dependent changes in BA synthesis that modulates PSC pathophysiology. In a genetic mouse model of PSC, we show that loss of microbiota-mediated negative feedback control of BA synthesis results in increased hepatic BA concentrations, disruption of bile duct barrier function and, consequently, fatal liver injury. We further show that these changes are dependent on decreased BA signalling to the farnesoid X receptor, which modulates the activity of the rate-limiting enzyme in BA synthesis, CYP7A1. Moreover, patients with advanced stages of PSC show suppressed BA synthesis as measured by serum C4 levels, which is associated with poor disease prognosis. Our preclinical data highlight the microbiota-dependent dynamics of BA metabolism in cholestatic liver disease, which could be important for future therapies targeting BA and gut microbiome interactions, and identify C4 as a potential biomarker to functionally stratify patients with PSC and predict disease outcomes. Patients with primary sclerosing cholangitis (PSC), a chronic cholestatic liver disease, display changes in the gut microbiota and in bile acid composition. Schneider, Candels and colleagues identify a role for microbiota-dependent regulation of bile acid synthesis through farnesoid X receptor signalling, which is relevant for PSC disease progression.
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| 133. |
- Schneider, K. M., et al.
(författare)
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Imbalanced gut microbiota fuels hepatocellular carcinoma development by shaping the hepatic inflammatory microenvironment
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths worldwide, and therapeutic options for advanced HCC are limited. Here, we observe that intestinal dysbiosis affects antitumor immune surveillance and drives liver disease progression towards cancer. Dysbiotic microbiota, as seen in Nlrp6(-/-) mice, induces a Toll-like receptor 4 dependent expansion of hepatic monocytic myeloid-derived suppressor cells (mMDSC) and suppression of T-cell abundance. This phenotype is transmissible via fecal microbiota transfer and reversible upon antibiotic treatment, pointing to the high plasticity of the tumor microenvironment. While loss of Akkermansia muciniphila correlates with mMDSC abundance, its reintroduction restores intestinal barrier function and strongly reduces liver inflammation and fibrosis. Cirrhosis patients display increased bacterial abundance in hepatic tissue, which induces pronounced transcriptional changes, including activation of fibro-inflammatory pathways as well as circuits mediating cancer immunosuppression. This study demonstrates that gut microbiota closely shapes the hepatic inflammatory microenvironment opening approaches for cancer prevention and therapy. Steatohepatitis is a chronic hepatic inflammation associated with increased risk of hepatocellular carcinoma progression. Here the authors show that intestinal dysbiosis in mice lacking the inflammasome sensor molecule NLRP6 aggravates steatohepatitis and accelerates liver cancer progression, a process that can be delayed by antibiotic treatment.
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| 134. |
- Schoonejans, Josca M., et al.
(författare)
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Serum bile acid measurements in women of European and South Asian ethnicity with or without gestational diabetes mellitus: A cohort study
- 2024
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Ingår i: BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY. - 1470-0328 .- 1471-0528. ; 131:9, s. 1218-1228
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Investigation of serum bile acid profiles in pregnancies complicated by gestational diabetes mellitus (GDM) in a multi-ethnic cohort of women who are lean or obese. Design: Prospective cohort study. Setting: UK multicentre study. Population: Fasting serum from participants of European or South Asian self-reported ethnicity from the PRiDE study, between 23 and 31 weeks of gestation. Methods: Bile acids were measured using ultra-performance liquid chromatography-tandem mass spectrometry. Log-transformed data were analysed using linear regression in STATA/IC 15.0. Main outcome measures: Total bile acids (TBAs), C4, fasting glucose and insulin. Results: The TBAs were 1.327-fold (1.105-1.594) increased with GDM in European women (P = 0.003). Women with GDM had 1.162-fold (1.002-1.347) increased levels of the BA synthesis marker C4 (P = 0.047). In South Asian women, obesity (but not GDM) increased TBAs 1.522-fold (1.193-1.942, P = 0.001). Obesity was associated with 1.420-fold (1.185-1.702) increased primary/secondary BA ratio (P < 0.001) related to 1.355-fold (1.140-1.611) increased primary BA concentrations (P = 0.001). TBAs were positively correlated with fasting glucose (P = 0.039) in all women, and with insulin (P = 0.001) and the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (P = 0.001) in women with GDM. Conclusions: Serum BA homeostasis in late gestation depends on body mass index and GDM in ethnicity-specific ways. This suggests ethnicity-specific aetiologies may contribute to metabolic risk in European and South Asian women, with the relationship between BAs and insulin resistance of greater importance in European women. Further studies into ethnicity-specific precision medicine for GDM are required.
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| 135. |
- Schöler, Marc, 1987, et al.
(författare)
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Moderate variations in the human diet impact the gut microbiota in humanized mice
- 2024
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Ingår i: Acta Physiologica. - 1748-1708 .- 1748-1716. ; 240:3
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Tidskriftsartikel (refereegranskat)abstract
- AimDrastic diet interventions have been shown to promote rapid and significant compositional changes of the gut microbiota, but the impact of moderate diet variations is less clear. Here, we aimed to clarify the impact of moderate diet variations that remain within the spectrum of the habitual human diet on gut microbiota composition.MethodsWe performed a pilot diet intervention where five healthy volunteers consumed a vegetarian ready-made meal for three days to standardize dietary intake before switching to a meat-based ready-made western-style meal and high sugar drink for two days. We performed 16S rRNA sequencing from daily fecal sampling to assess gut microbiota changes caused by the intervention diet. Furthermore, we used the volunteers' fecal samples to colonize germ-free mice that were fed the same sterilized diets to study the effect of a moderate diet intervention on the gut microbiota in a setting of reduced interindividual variation.ResultsIn the human intervention, we found that fecal microbiota composition varied between and within individuals regardless of diet. However, when we fed the same diets to mice colonized with the study participants' feces, we observed significant, often donor-specific, changes in the mouse microbiota following this moderate diet intervention.ConclusionModerate variations in the habitual human diet have the potential to alter the gut microbiota. Feeding humanized mice human diets may facilitate our understanding of individual human gut microbiota responses to moderate dietary changes and help improve individualized interventions.
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| 136. |
- Shemer, E. A. W., et al.
(författare)
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Intrahepatic cholestasis of pregnancy and cancer, immune-mediated and cardiovascular diseases: A population-based cohort study
- 2015
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Ingår i: Journal of Hepatology. - : Elsevier BV. - 0168-8278 .- 1600-0641. ; 63:2, s. 456-461
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease in pregnancy. It is associated with hepatobiliary diseases that might predispose to cancer and also with gestational diabetes and preeclampsia. In this study, we examined associations between ICP and cancer, and immune-mediated and cardiovascular diseases. Methods: By linking the Swedish Medical Birth Register and the Swedish Patient Register, we identified 11,388 women with ICP and 113,893 matched women without ICP who gave birth between 1973 and 2009. Diagnoses of cancer and immune-mediated and cardiovascular diseases both before and after delivery were obtained from the Patient Register. The main outcome measures were hazard ratios (HRs), calculated through Cox regression, for the indicated diseases after delivery. Results: ICP was not associated with later overall cancer (HR 1.07, 95% confidence interval [CI] 0.94-1.21), but it was associated with later liver and biliary tree cancer (HR 3.61, 95% CI 1.68-7.77, and 2.62, 95% CI 1.26-5.46, respectively). ICP was also associated with later immune-mediated diseases (HR 1.28, 95% CI 1.19-1.38), and specifically diabetes mellitus (HR 1.47, 95% CI 1.26-1.72), thyroid disease (HR 1.30, 95% CI 1.14-1.47), psoriasis (HR 1.27, 95% CI 1.07-1.51), inflammatory polyarthropathies (HR 1.32, 95% CI 1.11-1.58) and Crohn's disease (HR 1.55, 95% CI 1.14-2.10), but not ulcerative colitis (HR 1.21, 95% CI 0.93-1.58). Women with ICP also had a small increased risk of later cardiovascular disease (HR 1.12, 95% CI 1.06-1.19). Conclusions: Women with ICP have increased risk of later hepatobiliary cancer and immune-mediated and cardiovascular diseases. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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| 137. |
- Shemer, E. Wikström, et al.
(författare)
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Intrahepatic cholestasis of pregnancy and associated adverse pregnancy and fetal outcomes : a 12-year population-based cohort study
- 2013
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Ingår i: British Journal of Obstetrics and Gynecology. - : Wiley-Blackwell. - 1470-0328 .- 1471-0528. ; 120:6, s. 717-723
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To determine the risk for adverse pregnancy and fetal outcomes in intrahepatic cholestasis of pregnancy (ICP).Design: Population-based cohort study.Setting: Swedish Medical Birth Register (MBR) 19972009.Population: A total of 1213668 singleton deliveries.Methods: Linkage of Hospital Discharge Register for exposure (ICP; n=5477) with MBR for covariates.Main outcome measures: Gestational diabetes, pre-eclampsia, prematurity, and stillbirth.Results: Intrahepatic cholestasis (ICP) was diagnosed in 0.320.58% of all pregnancies, with an increasing trend until 2005 (P<0.0001). Compared with women who did not have ICP, women with ICP were more likely to have gestational diabetes (adjusted odds ratio, aOR, 2.81; 95% CI 2.323.41) and pre-eclampsia (aOR 2.62, 95% CI 2.322.78). Women with ICP were also more likely to have spontaneous (aOR 1.60, 95% CI 1.471.93) and iatrogenic (aOR 5.95, 95% CI 5.236.60) preterm delivery, with increased rates of induction of labour (aOR 11.76, 95% CI 11.0411.62). However, this actively managed cohort of ICP cases was not at increased risk of stillbirth (aOR 0.92, 95% CI 0.521.62). Infants in ICP deliveries were more likely to have a low (<7) 5-minute Apgar score (aOR 1.45, 95% CI 1.141.85) and be large for gestational age at birth (aOR 2.27, 95% CI 2.022.55).Conclusions: Over time, a greater proportion of Swedish pregnant women have received a diagnosis of ICP, probably because of an increased awareness of the disorder. Our data confirm an increased risk of preterm delivery, but not of stillbirth, in actively managed ICP. The high rates of gestational diabetes and pre-eclampsia are new findings, and need to be considered in the management of ICP pregnancies.
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| 138. |
- Shemer, E. W., et al.
(författare)
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Stereological assessment of placental morphology in intrahepatic cholestasis of pregnancy
- 2012
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Ingår i: Placenta. - : Elsevier BV. - 0143-4004 .- 1532-3102. ; 33:11, s. 914-918
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To To apply stereology for the detection of possibly morphological abnormalities in placentas of women with intrahepatic cholestasis of pregnancy (ICP). Study design: Prospective case-control study of placentas from untreated and UDCA-treated ICP, respectively, and normal pregnancies, examined for morphological differences by systematic random sampling generated by computerized stereology methodology. Main outcome measures: Volume of placenta, surface area of terminal villi and capillaries, volume fraction of collagen, number of syncytial knots, and chorangiosis. Results: Surface area of terminal villi and capillaries, and number of syncytial knots were higher in placentas from all ICP, as compared to controls (p < 0.01). A reduction of collagen was found in placentas from UDCA-treated ICP, both in comparison to placentas from untreated ICP and controls (p < 0.05). Conclusion: ICP affects the placenta morphologically as shown by increased terminal villous and capillary surface area, and number of syncytial knots. (c) 2012 Elsevier Ltd. All rights reserved.
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| 139. |
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| 140. |
- Sjöland, Wilhelm, et al.
(författare)
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Absence of gut microbiota reduces neonatal survival and exacerbates liver disease in Cyp2c70-deficient mice with a human-like bile acid composition
- 2023
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Ingår i: Clinical Science. - 0143-5221. ; 137:13, s. 995-1011
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Tidskriftsartikel (refereegranskat)abstract
- Mice with deletion of Cyp2c70 have a human-like bile acid composition, display age-and sex-dependent signs of hepatobiliary disease and can be used as a model to study interactions between bile acids and the gut microbiota in cholestatic liver disease. In the present study, we rederived Cyp2c70-/- mice as germ-free (GF) and colonized them with a human or a mouse microbiota to investigate whether the presence of a microbiota can be protective in cholangiopathic liver disease associated with Cyp2c70-deficiency. GF Cyp2c70-/- mice showed reduced neonatal survival, liver fibrosis, and distinct cholangiocyte proliferation. Colonization of germ-free breeding pairs with a human or a mouse microbiota normalized neonatal survival of the offspring, and particularly colonization with mouse microbiota from a conventionally raised mouse improved the liver phenotype at 6-10 weeks of age. The improved liver phenotype in conventionalized (CD) Cyp2c70-/- mice was associated with increased levels of tauro-ursodeoxycholic acid (TUDCA) and UDCA, resulting in a more hydrophilic bile acid profile compared with GF and humanized Cyp2c70-/- mice. The hydrophobicity index of biliary bile acids of CD Cyp2c70-/- mice was associated with changes in gut microbiota, liver weight, liver transaminases, and liver fibrosis. Hence, our results indicate that neonatal survival of Cyp2c70-/- mice seems to depend on the establishment of a gut microbiota at birth, and the improved liver phenotype in CD Cyp2c70-/- mice may be mediated by a larger proportion of TUDCA/UDCA in the circulating bile acid pool and/or by the presence of specific bacteria.
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